Wiring-terminal device



March 0' R. A. MILLERMASTER 2,193,202

WIRING-TERMINAL DEVICE Filed March 13, 1939 Patented Mar. 12, 1940PATENT OFFICE WIRING-TERMINAL DEVICE Ralph A. Millcrmaster, Milwaukee,Wis., assignor toCutler-Hammer, Inc., Milwaukee, Wis., a corporation ofDelaware Applicatlon March 13. 1939, Serial No. 261,521

6 Claims.

This invention relates to improvements in wiring-terminal devices, andthe invention re Iates more particularly to improvements in theso-called clamp-type, solderless wiring terminals.

An object of the invention is to provide an electrically satisfactorywiring-terminal device of the aforementioned character which is ll'iOll.rugged and durable than such devices as heretofore constructed. 10Another object is to provide means for insuring against shearing orother damage to the circuit wire during operation of the terminal deviceto wire clamping position.

Another object is to provide novel means of alternative form forsupporting parts of the wiring-terminal device.

Another object is to provide a wiring-terminal device affording a verygood electrical connection and a very tight mechanical connectionbetween the same and a circuit wire.

Another object is to simplify the construction and facilitate assemblyof the parts of such wiring-terminal devices.

Other objects and advantages of the invention will hereinafter appear.

This application is a continuation in part of my application, Serial No.184,715, filed January 13, 1938, for fuse pull-out devices.

, The accompanying drawing illustrates certain embodiments of theinvention which will now be described, it being understood that theembodiments illustrated are susceptible of modification in respect ofcertain structural details without departing from-the scope of theappended claims.

In the drawing,

Figure 1 is a vertical sectional view of a clamptype, solderlesswiring-terminal device constructed in accordance with my invention, the

same being supported by a cooperatively formed metal conducting strip orbus member, which is in turn attached to a suitable insulating base.

Fig. 2 is a perspective view of the terminal device shown in Fig. 1, andillustrating the manner 45 in which the same is rigidly attached to abus member of suitable form.

Fig. 3 is a top plan view of the terminal device shown in-Figs. 1 and 2,the clamping screw or bolt being removed for purposes of illustration.

50 Fig. 4 is a vertical sectional view of a wiringterminal device whichmay be identical with that shown in Figs. 1 to 3, but having captivelyassociated therewith a clamping member to be interposed between theclamping end of the screw 55 and the circuit wire.-

(Cl. 1i3269) a Fig. 5 is a perspective view of the added clamping membershown in Fig. 4.

Fig. 6 is a side elevational view of a wiringterminal device like thatshown in Fig. 4, but

modified by omitting the rigid connection betweensaid device and the busmember (as shownin Figs. 2 and 3), the insulating base to which theparts may be attached, for retention thereof in assembled relation,being shown in vertical section. v

Fig; 7 is a top plan view of certain of the parts shown in Fig. 6, thescrew or bolt being removed, and the swaging or upsetting of the busmember (as shown in Figs. 2 and 3) being obviated.

Fig. 8 is a perspective view of the steel tube l6 section of rectangularform in transverse cross section which I prefer to employ, and

Fig. 9 is a perspective view of an end portion of the bus member, in itsintermediate form when employed as shown in Figs. 1 to 4, and in itsfinal form when employed as shown in Figs. 6 and '7.

Referring first to Figs. 1 to 3 and 8, the numeral l5 designates a stripmetal conductor or bus member which has alined portions of its oppositesides cut away to provide a headportion It, and a neck I! of a width andlength corresponding rather closely to the internal width and thelength, respectively, of a hollow metal member I8 of substantiallyrectangular form in trans- 0 verse cross section. Member [8 ispreferably formed by cutting or sawing the desired length thereof, froma seamless steel tube of substantially rectangular form in crosssection, as illustrated. 1

One wall of member it is provided with a relatively large tapped openingto accommodate the threaded shank of a screw IS, the diameter of whichshank is only slightly less than the width of the rectangular opening orpassage through member l8,- as indicated by the dotted lines in Fig. 3representing the inner surfaces of the side walls of member l8 and theside edges of the aforementioned neck portion ll of member IS. The headof the screw 19 is preferably of hexagonal (as shown) or other polygonalcontour, to provide for operation thereof by a suitable wrench, and thesame is also preferably provided with a kerf to alternatively providefor operation thereof by a screw driver. The lower end of screw I9 ispreferably flat, to provide a relatively large clamping area. However, Iprefer to provide the lower end of screw IS with a beveled or taperededge 20 (Fig. 1) to facilitate initial threading thereof into saidtapped opening.

With reference to Fig. 2, it is to be understood that member I8 isinitially tilted laterally in one direction or the other (prior toassembly of screw IS with respect thereto, or with said screwsuiilciently withdrawn to permit clearance for the head IS, in thecondition of the latter shown in Fig. 9, at diagonally opposite portionsor corners of the opening in said member l8). Member I8 is then turnedto upright position, as shown in Fig. 2, and while the neck I1 is heldagainst the inner surface of the lower wall of the opening in member l8,a pair of integral lugs 2| and 22 (Fig 3) are swaged or bent inwardlyfrom opposite side edges of the member l5 into engagement with theexterior walls of member l8; and opposite ends of head l6 are swagedagainst the forward edges of the respective side walls of member l8, asshown at 23 and 24 in Figs. 2 and 3, to rigidly and permanently securemember ill to member I 5.

The exposed surface of neck I! within member i8 is preferably providedwith a series of parallel grooves and ridges 25, the grooves as shownbeing V-shaped, and the same being sumciently spaced from each other toafiord flat upper surfaces 26 for the ridges formed therebetween. Saidexposed surface of neck I I may, of course, be roughened in any otherdesired manner, to provide a proper gripping surface for the conductoror wire pressed thereagainst by tightening of the clamping screw I 9. Aswill be understood, the flat lower end of the shank of screw l9 acts toclamp a conductor tightly and directlyagainst the copper bus member l5;and hence both member l3 and screw l9 may be formed of steel, to insureproper strength and durability of these parts.

Bus member i5 may be provided with a tapped opening 21 for cooperationwith the threaded shank of a screw or bolt 28 which is used to clampmember l5 to a suitable insulating base, such as shown at 29 in Fig. 1.As aforedescribed in connection with Figs. 1 to 3, member I8 is rigidlyattached to the free end of member l5 in a manner to provide for supportof the former out of engagement with base 29. However, the member I8 01'the device shown in Figs. 1 to 3, might be positioned as shown in Fig. 6with respect to an insulating base such as shown at 30, to provide abacking for member I3, and to relieve any bending strain upon bus memberl5 as an incident to tightening of the screw IS.

with a supporting arrangement such as shown in Fig. 6 it is of courseunnecessary to rigidly unite member l8 directly to member l5, thusobviating the necessity for upsetting member I5 in the manner shown at2|, 22 and 23, 24 in Figs. 2 and 3. That is to say, with members l8 andI5 loosely assembled with respect to each other as shown in Figs. 4, 6and '7, and with member l5 attached to base 30 by screw 3| as shown inFig. 6, tilting movement of member l8 relatively to member I5 isprevented by engagement of the former with shoulder or ledge 32 of base30, and head N5 of member l5 acts to prevent endwise displacement ofmember IS with respect thereto.

As shown in Fig. 4, upon tightening of screw I 9 the conductor or wire,such as 33, will be clamped with the desired degree of pressure againstthe grooved and ridged or otherwise roughened neck portion ll of memberIS, the ridges being adapted to bite into or positively engage the wire33 upon application of a suflicient degree of pressure thereon byoperation of screw 19. In order to insure application of the clampingpressure in a straight line against the upper surface of the wire orconductor 33, an to prevent distortion, twisting or cutting of t e wireby the lower end of screw [9, I prefer to interpose between the latterand the wire the 5 flat or plate portion 34 of an auxiliary metalclamping member (preferably formed of steel). Said member is providedwith an integral intermediate curved or bowed portion 35 and a portion36 substantially parallel with portion 34; 1 portion 36 being providedwith an eye or opening 31 (Fig. 5) to accommodate the shank of screw l9,whereby said auxiliary clamping member is held captive in properlyassembled relation to the other parts, as shown in Fig. 6. 1

As will be apparent from consideration of Fig. 6, the curved portion 35of said auxiliary clamping member acts as a guide to facilitateinsertion of the bared end of the wire 33 (Fig. 4) between portion 34and the upper surface of neck 2 portion l1, said auxiliary member beingfree to move vertically upwardly to freely accommodate said wire,assuming a proper degree of withdrawal of screw l9, as shown in Fig. 6.Thereafter upon tightening of screw H! the lower end 2 of the latterengages portion 34 to press the same in a straight line against theupper surface or edge of the wire 33, as indicated in Fig. 4.

It is to be understood that the auxiliary clamping member of Fig. 5 maybe used in conjunc- 3 tion with the device of Figs. 1 to 3; and,conversely, that said auxiliary clamping member may be omitted orremoved from the device shown in Figs. 4, 6 and 7.

What I claim as new and desire to secure by 3 Letters Patent is:

1. In a device of the character described, in combination, a copper busmember having a portion of reduced width adjacent to one end thereofwhereby a head and two sets of spaced shoulders are provided, a steeltube section of substantially rectangular contour having a lengthsubstantially corresponding to the distance between the shoulders ofsaid sets and an internal width substantially corresponding to the widthof said reduced portion, said head being diagonally inserted throughsaid tube section and thereafter turned to provide for seating of saidreduced portion against the bottom wall of said tube section, portionsof certain of said shoulders being upset against the outer surfaces ofthe side walls of said tube section to rigidly and permanently securethe latter to said bus member, the upper end wall of said tube sectionhaving a tapped opening formed therein, a metal member having anoperating head portion and a threaded shank portion for engagement withsaid opening, said shank portion being movable toward said bus memberwhereby a conductor when inserted into said tube section is clampedagainst the reduced portion of said bus member, and said metal memberhaving its operating head portion exposed at the upper surface of saidtube section.

2.'A solderless wiring terminal comprising a copper bus member having ae portion of reduced width and a neck portion of further reduced widthwhereby two sets of longitudinally spaced shoulders are provided, a coldrolled steel tube section of substantially rectangular contour having alength to be accommodated between the 7 shoulders of said sets and aninternal width to accommodate said reduced portion, said tube sectionbeing turned diagonally and moved over said head portion and the samebeing thereafter turned upright to seat the bottom wall thereof 7against the lower surface of said neck portion, the side edges of saidbus member adjacent to the inner end of said tube section being upsetover the outer surfaces of the side walls of the latter to rigidly andpermanently secure said tube section to said bus member, the uppersurface of said neck portion being formed to provide alternate groovesand ridges, the upper end wall of said tube section having a tappedopening formed therein, a cold rolled steel screw the shank of which hasthreaded engagement with said opening and which shank has asubstantially flat end movable toward said grooves and ridges whereby aconductor when inserted into said tube section is clamped against saidgrooves and ridges, and said screw having a kerfed head of polygonalcontour to provide for operation thereof by alternative means.

3. In a device of the character described, in combination, a flat busmember of copper or similarly highly conductive metal having a portionof reduced width adjacent to but spaced from one end thereof whereby ahead and two sets of spaced shoulders are provided, a seamless steeltube section of polygonal contour in transverse cross section having alength substantially corresponding to the distance between therespective sets of shoulders and an internal width substantiallycorresponding to the width of said reduced portion, said head beingtilted for insertion thereof through said tube section and the samebeing thereafter turned to provide for seating of said reduced portionagainst the bottom wall of said tube section, the upper end wall of saidtube section having a tapped opening formed therein, a steel screw theshank of which has threaded engagement with said opening, said shankbeing movable vertically toward the reduced portion of said bus member,for the purpose set forth, and said screw having an operating headportion exposed at the upper surface of said tube section.

4. In a device of the character described, in combination, a list busmember of copper or similar highly conductive metal having a portion ofreduced width adiacent to but spaced from one end thereof whereby a headand two sets of spaced shoulders are provided, a seamless steel tubesection of polygonal contour in transverse cross section having a lengthsubstantially corresponding to the distance between the respective setsof shoulders and an internal width substan-- tially corresponding to thewidth of said reduced portion, said head being tilted for ,insertionthereof through said tube section and the same being thereafter turnedto provide for seating of said reduced portion against the bottom wallof said tube section, the upper end wall of said tube section having atapped opening formed therein, a steel screw the shank of which hasthreaded engagement with said opening, said screw having an operatinghead portion exposed at the upper surface of said tube section, and anauxiliary metal clamping member of approximateiy U-shap'e in transversecross section, one arm of said U being positioned above said tubesection and having an opening to freely accommodate the shank of saidscrew. the other arm of said U being positioned within said tube sectionand underlying said shank for free straight line movement by the lattertoward the reduced portionofsaidbusmembeaforthem mleset orth.

5'. In a device of the character described, in combination, a flat busmember of copper or similar highly conductive metal having a portionofreduced width adjacent to but spaced from one end thereof whereby a headand two sets of spaced shoulders are provided, a seamless steel tubesection of substantially rectangular contour in transverse cross sectionhaving a length substantially corresponding to the distance between therespective sets of shoulders and an internal width substantiallycorresponding to the width of said reduced portion, said head beingtilted for insertion thereof through said tube section in a diagonalrelationship-to the latter and thereafter turned to provide for seatingof said reduced portion against the bottom wall of saidtube section, theupper end wall of said tube section having a tapped opening formedtherein, a steel screw the shank of which has threaded engagement withsaid opening, said shank being movable vertically toward the reducedportion of said bus member, for the purpose set forth, said screw havingan operating head portion exposed at the upper surface of said tubesection, a molded insulating base having a surface to which said busmember is rigidly secured, and said base having a ledge. formed thereonand underlying the aforementioned end of said bus member to snuglyaccommodate the lower end wall of said tube section, whereby said basecooperates with said bus member to positively retain said tube sectionin assembled position.

6. In a device of thecharacter described, in combination, a flat busmember of copper or similar highly conductive metal having a portion ofreduced width adjacent to but spaced from' insertion thereof throughsaid tube section in a, diagonal relationship to the latter andthereafter turned to provide for seating of said reduced portion againstthe bottom wall of said tube 7 section, the upper end wall of said tubesection having a tapped opening formed therein, a steel screw the shankof which has threaded engagement with said opening, said screw having anoperating head portion exposed at the upper sur-' sembled position, andan auxiliary sheet metal' clamping member bent to approximately U-shapein transverse cross section, one arm of said U being positioned abovesaid tube section and having an opening to fr ely accommodate the shankof said screw, and the other arm of said U being positioned within saidtube section and underlyingtheshankofsaidscrewforfreestraight linemovement by the latter toward the reduced (0 portion of said bus member,for the P p set forth.

RALPH A. V

